Most of us visit the doctor only when we’re sick or injured. We break an ankle, get walloped with the flu, and finally dial up our physician or nurse practitioner to tell them where it hurts.

The Affordable Care Act seeks to change that. While the health reform law can’t quell your fear of needles or force your stubborn husband to schedule a physical, it’s nudging you to think about your health even when you feel well, by appealing to you where it counts. Your wallet.

Since 2010, the law has required most private health plans to cover a range of preventive care services to adults and children with no “cost-sharing.” In plain English, that means at no cost to you. Blood pressure and cholesterol tests, colonoscopies, vaccines and other services must be provided without charging you a co-pay or co-insurance, even if you haven’t met your yearly deductible.

Also included are additional preventive services for women, such as breast cancer screenings and all contraceptive methods approved by the U.S. Food and Drug Administration. You may recall the outcry earlier this year over the birth control inclusion, and months of protest by religious groups and others who argued that the act forced them to violate religious tenets against contraception. In February, the White House offered a compromise that exempts nonprofit, religious employers that object to that requirement.

Consumers are less likely to get preventive care when they have to fork over a payment, explains Mitchell Stein, policy director at Consumers for Affordable Health Care, an Augusta advocacy group.

“Study after study has shown that the presence of a co-pay or co-insurance impedes [the use] of services,” he said.

In other words, make it free, and we’re more likely to wince our way through a less-than-pleasant colonoscopy or mammogram.

Another goal of the preventive care requirement is to open the door to a new type of relationship between health practitioners and their patients, one that’s less about periodic complaints and more about overall wellness, said Wendy Wolf, president and CEO of the Maine Health Access Foundation.

“By eliminating cost-sharing for preventive benefits, we’re trying to encourage people to have earlier testing so that we can catch significant illnesses earlier in the course and intervene before they become more costly,” she said.

The preventive care requirement applies to private health plans purchased both on and off the new health insurance marketplaces, where small businesses and consumers can shop for coverage come Oct. 1. So if you’re in the “individual market,” meaning you buy your own plan and will shop on the marketplace, you’ll benefit. The requirement also applies to employer plans, so if you have coverage through work, preventive services are probably free.

Here’s the big exception: The free preventive care rights don’t apply to health plans already in place when health reform became law on March 23, 2010. Those policies, known as grandfathered plans, are exempt from many provisions of the law.

A fair number of folks have grandfathered plans. More than a third of all Americans who get insurance through their jobs are enrolled in them, according to the Kaiser Family Foundation’s most recent Employer Health Benefits Survey. In Maine, just fewer than half of the roughly 18,400 people covered through individual policies sold by Anthem Blue Cross and Blue Shield, the biggest insurer in that market, are in grandfathered plans.

But more plans are expected to lose grandfathered status over time. If an insurer or employer significantly changes a plan’s benefits or how much members pay in premiums, co-pays or deductibles, they can kiss grandfathered status goodbye.

Otherwise, the free preventive care requirement applies to all private policies issued or renewed on or after Sept. 23, 2010. Women gained access to additional services without cost-sharing a bit later, for policies renewing on or after Aug. 1, 2012.

What if you have government health insurance?

This provision of the ACA doesn’t apply to Medicaid, the joint state-federal health insurance program for low-income Americans. The law offered states more federal money if they chose to have their Medicaid programs cover some additional immunizations and certain preventive services without charging a co-pay, but Maine declined to implement that part of the law.

However, the program, known as MaineCare here in Maine, already covers a number of preventive services with no co-pay when the care is received at a doctor’s office. MaineCare also doesn’t charge co-pays for services provided to children and pregnant women. To learn if a particular service is covered, call MaineCare member services at 800-977-6740.

If you’re enrolled in Medicare, the government health insurance program for senior citizens and the disabled, you’re already benefiting from a similar provision of the law. As of 2011, Medicare covers many preventive services without cost-sharing. In Maine, 168,602 individuals with traditional Medicare used one or more free preventive services in 2012, according to the U.S. Department of Health and Human Services.

Medicare beneficiaries can also schedule an annual free “wellness visit” with their doctor. You won’t have to wear a johnny for that one. Unlike an annual physical, the wellness visit is an opportunity to talk to your doctor about your overall health, without an exam, Stein said.

Wait, what about that saying, “There’s no such thing as a free lunch?” Critics and even some supporters of the ACA point out that it costs employers and insurers money to provide patients with preventive care, so it’s not really “free” at all.

That’s true, Stein said. The idea, though, is that wrapping the cost of preventive services into the insurance premiums consumers pay — rather than nickel-and-diming them with co-pays and co-insurance — “encourages their use and helps people stay healthy,” he said.

Anthem estimates the preventive care requirement boosted the premium costs for its plans about 1.5 percent (among plans that didn’t already fully cover those services before the ACA), according to company spokesman Chris Dugan. That’s not nothing, but it’s also not a major driver of premiums, unlike some other provisions of the law.

The libertarian Cato Institute warns that the preventive care requirement robs consumers of the incentive to choose cost-effective care, since they’re not paying for it. Subsequently, health providers have little motivation to compete on price, the Washington, D.C., think tank argues.

Wolf points out that many private health plans and employers offered free coverage for preventive services even before the ACA came along, recognizing that workers would be healthier and therefore less expensive to cover in the long run.

“This is the way the private market has been moving and a policy that is hand-in-glove with a lot of the large employers saying, ‘Hey we want to move more toward wellness and early intervention,’” she said.

With health insurance, there’s always a “but.” A few things to keep in mind:

• To get preventive care at no cost, you have to see a provider in your plan’s network of approved doctors and health practitioners. The benefit doesn’t apply if you see a doctor outside the network.

• Some people may run into trouble getting colonoscopies covered at no cost. Stein was one of them, he said. There was some early confusion about whether the preventive care requirement applied if, for example, a patient scheduled a colonoscopy as a preventive measure but the doctor ended up finding and removing a polyp. The feds clarified the rules last year, but “some insurers haven’t caught up with it yet,” Stein said. All care received in conjunction with a preventive colonoscopy should be covered, he said. If you get charged, call your insurance company.

• For the visit to be paid for in full, you must see your doctor for the specific purpose of preventive care. If you have a screening or blood test for medical reasons other than prevention, you’ll likely have to pay for some of it.

• Your plan may cover other preventive services beyond the government’s list of recommended preventive services. You may have to pay for those.

• If you get coverage through your employer, you can still join a grandfathered plan even if you weren’t enrolled on March 23, 2010.